Fuel pump



W. H. SHOPE Dec. 14, 1965 FUEL PUMP Filed May 4, 1959 3 Sheets-Sheet 1 INVENTOR. WILLIHM H. cSHOPE #YraPf/VEMS W. H. SHOPE Dec. 14, 1965 FUEL PUMP 5 Sheets-Sheet 2 Filed May 4, 1959 M an m M w 7 Z W, a; 7 J a 9 4% Z a 5. 2 WW5 My y A, 2

INVENTOR. WILLIAM H. 5H0PE W. H. SHOPE Dec. 14, 1965 FUEL PUMP 3 Sheets-Sheet 5 Filed May 4, 1959 I I I 7 E MWW m W6 M 2 1HM m 1 M M g L oomwfi z W 00 u a v y 7% 5: 5 a L 1 r./%

United States Patent ()fifice I),ZZ3,045 Patented Dec. 14, 1965 3,223,045 FUEL PUMP William H. Shope, Clawson, Mich., assignor to Chrysler Corporation, Highland Park, Mich., a corporationof Delaware Filed May 4, 1959, Ser. No. 810,873 7 Claims. (Cl. 103-450) This invention relates to improvements in fuel pumps of the type used on internal combustion engines and designed to deliver a constant supply of fuel to the engine in accordance with engine demands.

In fuel pumps of this type certain features are very desirable such as structure which lends to easy pump installation and repair, means to limit the maximum output pressure of the pump, means to control the output pressure of the pump independent of the pumping force exerted by the direct acting camshaft pump actuator construction, and stamped structure eliminating housing castings, and direct actuating mechanism eliminating such structure as rocker arms and associated linkages which are conventionally provided on fuel pumps.

A principal object of this invention is to provide a pump utilizing the above noted desirable features.

A specific object is to provide a pump wherein the actuating rod passes through the diaphragm and provides a direct power connection from the engine camshaft to the pumping diaphragm.

Another object is to provide the pump in the preceding object with a means to prevent excessive pressure buildup in the pump and limit the effect of the force output of the camshaft.

Further objects and advantages will become apparent from the following description and drawings, in which: FIGURE 1 represents a side view of a fuel pump;

FIGURE 2 represents a cross sectional view of the pump of FIGURE 1 taken along the line 22 thereof in the direction of the arrows;

FIGURE 3 represents a cross sectional view of the fuel pump of FIGURE 1 taken along the line 33 thereof in the direction of the arrows;

FIGURE 4 represents a cross sectional view of the fuel pump of FIGURE 1 taken along the line 44 thereof in the direction of the arrows;

FIGURE 5 represents a cross sectional view of the pump of FIGURE 2 taken along the line 55 thereof in the direction of the arrows;

FIGURE 6 represents a cross sectional view of a fuel pump of FIGURE 2 taken along the line 66 thereof in the direction of the arrows; and

FIGURE 7 represents a modification of the fuel pump of FIGURES 1 through 6.

Referring to the drawings, a fuel pump designated generally as 10 is comprised of an upper sheet metal cover 12, a center casting 14 and a lower casting 16. Castings 14 and 16 are secured together by bolts 18 and cover 12 is connected to casting 14 by screws 20. In the structure of FIGURES 1-6 two inlet ports 22 are provided in casting 14 and communicate with a chamber generally designated 24 which is formed by casting sections 14 and 16 as shown in FIGURE 5. A fuel inlet line 26 connects chamber 24 with a fuel source. A check valve generally designated 28 is pressed into casting 14 and into ports 22 and allows fuel to flow in one direction only toward the diaphragm 30 in response to the diaphragm 30 moving away from the ports 22. These check valves 28 consist of a valve shell 32 having ports 34 therein, a valve seat 36 having a fuel aperture 38 therein, and a valve disc 40 constantly urged toward seat 36 by a spring 42. Also provided in section 14 is an outlet port 44 which opens into a chamber 46 formed in section 14 and limited in size by a flexible diaphragm member 48 which also defines a chamber 50 in section 16 which chamber 50 is air filled and acts as a fuel outlet pulse modifier or stabilizer in that it prevents the transmission of excessive fuel pulsations to the fuel outlet line 52. A check valve 54 is provided in port 44 and is identical in construction to valve 28 but operates in a different direction to prevent a back flow of pump fuel.

The diaphragm 30 is made rigid over a large portion thereof by an annular bot-tom metal plate 56 which is secured to the diaphragm by adhesion or other suitable means such as the rivet 57 shown in FIGURE 7 and is rigidified on its top surface by the annular metal plate 58 which is formed into a neck 59 and shoulder 60' to provide a stop means for the diaphragm actuating member 62. Actuator member 62 in the shape of a rod is slidably received in the lower casting 16 and in a threaded bushing 64 threadedly received in the upper casting 14. Actuator 62 is provided at its upper end with a shoulder 66 which abuts a metal washer 68 and a plastic material sound deadener 70 which in turn abuts the shoulder 60 of the rigid support 58 to impart a pumping force'to the diaphragm 30 when the actuator 62 is moved upwardly from the position shown in FIGURE 5. The diaphragm 30 is annular in shape to receive the threaded bushing 64 and is securely fastened to the casting 14 by a washer 72 and bushing 64 bearing against a shoulder 74 on the upper casting 14 to provide a fluid tight seal. Another diaphragm sealing member 76 is securely fastened to the actuator rod 62 and between the castings 14 and 16 to provide a fluid tight seal for any oil that might tend to leak upwardly along actuator 62 from the interior of the engine.

A helical spring 78 interposed between housing 12 and support member 58 urges support 58 and diaphragm 30 in its downward position as shown in FIGURE 5 and reacts against the pumping force of the actuator member 62 as actuated by the camshaft 63 of the engine. It is seen that as the pressure of the fuel underneath diaphragm 30 becomes sufiicient to overcome the force of spring 78 the diaphragm and support member 58 will be urged upwardly to such a position that annular flange 60 of member 58 will not abut the sound deadening washer 70 even when the actuator member 62 is in its upmost cam actuated position. In this manner the maximum pressure output of the pump can be regulated and any actuating force exerted on member 62 by the camshaft once spring 78 has been overcome by the pump pressure is ineffective to further move the diaphragm and pump fuel through the check valve 54 until the pressure in the pump diminishes. A following spring 80 is provided to urge the actuator member 62 into constant contact with the camshaft of the engine.

In the pump variation shown in FIGURE 7 having the same check valve structure as FIGURE 5, the actuator rod 82 is secured to the rigid diaphragm support member 84, and the diaphragm 83 consequently moves with the rod 82. Rod 82, however, is maintained in spaced relation from the camshaft of the engine when the pump pressure as predetermined by design is sufficient to overcome the force of spring 86. It is noted that in this structure of FIGURE 7 the pulsation takeup chamber 50 of FIG- URE 5 is lacking and slight modifications in the design of the sheet metal casing 81, housing section 89, diaphragm rigidifying members 84 and 85, spring 86, and sealing means 87 are readily apparent. Also, the following spring 80 of FIGURES 5 and 6 is not required since the rod 82 does not follow the camshaft after a certain pressure is built up underneath diaphragm 83.

A mounting flange 88 as shown in FIGURE 1 may be provided on both types of pumps at any desirable angle for facilitating mounting of the pumps on the engine, or as shown in FIGURE 7 a mounting stud 90 may be provided for direct attachment into a mating aperture in the engine and an adjusting and lock nut 92 may be used to regulate the insertion of the stud 90 into the engine to properly set and lock the pump actuator rods relative to the camshaft.

I claim:

1. A fluid pump comprising a housing having an inlet port and an exhaust port therein, valve means in each said port for preventing fluid flow therethrough in one direction, peripheral and inner shoulder means on said housing, annular diaphragm means secured to said housing along said peripheral shoulder means and said inner shoulder means and forming an annular fluid tight chamber communicating with said inlet and exhaust ports, a rigid support extended over and aflixed snugly to a major portion of said diaphragm means thereby making the major portion of said diaphragm means substantially inflexible while providing flexible portions adjacent each said shoulder means, actuating means reciprocably mounted in said housing, said actuating means passing through the annulus of said diaphragm means and having shoulder means adapted for abutting and exerting an actuating force on said rigid support to move the same and said diaphragm means with respect to said inlet and exhaust ports, and resilient means exerting a reaction force on said diaphragm means in a direction opposing said actuating force to pressurize the fluid within said pump.

2. A fluid pump comprising a houisng having an inlet port and an exhaust port therein, valve means in each said port for preventing fluid flow therethrough in one direction, peripheral and inner shoulder means on said housing, peripheral annular diaphragm means secured to said housing along said peripheral shoulder means and said inner shoulder means and forming an annular fluid tight chamber communicating with said inlet and exhaust ports, a rigid support extended over and aflixed snugly to a major portion of said diaphragm means thereby making the major portion of said diaphragm means substantially inflexible while providing flexible portions adjacent each said shoulder means, actuating means reciprocably mounted in said housing, said actuating means passing through the annulus of said diaphragm means and having shoulder means adapted for abutting and exerting an actuating force on said rigid support to move the same and said diaphragm means with respect to said inlet and exhaust ports, and resilient means exerting a reaction force on said diaphragm means in a direction opposing said actuating force to pressurize the fluid within said pump, said reaction force having a maximum value limiting the maximum output pressure of said pump.

3. A fluid pump comprising a housing having an inlet port and an exhaust port therein, valve means in each said port for preventing fluid flow therethrough in one direction, peripheral and inner shoulder means on said housing, annular diaphragm means secured to said housing along said peripheral shoulder means and said inner shoulder means and forming an annular fluid tight chamber communicating with said inlet and exhaust ports, a rigid support extended over and aflixed snugly to a large portion of said diaphragm means thereby making the large portion of said diaphragm means substantially inflexible while providing flexible portions adjacent each said shoulder means, actuating means reciprocably mounted in said housing, said actuating means passing through the annulus of said diaphragm means and having shoulder means adapted for abutting and exerting an actuating force on said rigid support to move the same and said diaphragm means with respect to said inlet and exhaust ports, and resilient means exerting a reaction force on said diaphragm means in a direction opposing said actuating force to pressurize the fluid within said pump.

4. A pump comprising a cupshaped body having a central hub, said hub having an axial opening, a diaphragm having a center hole registering with the opening in the hub, the diaphragm having its inner margin around its center hole sealed to the hub around the opening in the hub and having its outer margin sealed to the wall of the cup-shaped body with an intermediate annular portion of the diaphragm between said hub and wall constituting an annular slack loop free for flexure, thereby providing an annular pump chamber on the side of the diaphragm toward the body adapted to be expanded and contracted by said loop, said body having a valved inlet and a valved outlet for said chamber, a cup-shaped casing having a rim portion secured in sealed relation to the loop on the other side of the diaphragm, and means for actuating the casing to actuate the diaphragm.

5. A pump comprising a body having a cup-shaped portion and a central hub extending from the bottom of said cup-shaped portion, a diaphragm having a center hole registering with said hub, said diaphragm having its inner margin around its center hole sealed to said body portionaround said hub and having its outer margin sealed to the wall of the cup-shaped body portion with an intermediate angular portion of the diaphragm between said hub and wall constituting an annular slack loop free for flexure thereby providing an annular pump chamber on the side of the diaphragm toward said body, said body having a valved inlet and a valved outlet for said chamber, a cup-shaped casing extending over said hub and having a rim portion secured to the loop on the other side of said diaphragm, and means for actuating the casing to actuate the diaphragm to expand and contract said pump chamber.

6. A fluid pump comprising a housing having an inlet port and an exhaust port therein, valve means in each said port for preventing fluid flow therethrough in one direction, peripheral and inner shoulder means on said housing, annular diaphragm means secured to said housing along said peripheral shoulder means and said inner shoulder means and forming an annular fluid tight chamber communicating with said inlet and exhaust ports, a rigid support extended over and aflixed snugly to a large portion of said diaphragm means thereby making the large portion of said diaphragm means substantially inflexible while providing flexible portions adjacent each said shoulder means, actuating means reciprocably mounted in said housing, said actuating means passing through the annulus of said diaphragm means and having shoulder means adapted for abutting and exerting an actuating force on said rigid support to move the same and said diaphragm means with respect to said inlet and exhaust ports, and resilient means exerting a reaction force on said diaphragm means in a direction opposing said-actuating force to pressurize the fluid within said pump, said reaction force having a maximum value limiting the maximum output pressure of said pump.

7. A pump as set forth in claim 3 wherein the diaphragm means is sealed to the housing around the opening in said annulus by tubular clamp means extending through said opening and secured to said housing, said clamp means having a flange engaging the diaphragm around said opening, said actuating means extending through said tubular clamp means.

References Cited by the Examiner UNITED STATES PATENTS 2,764,942 10/1956 Guarnaschelli et al. 103150 X 2,774,380 12/1956 Hudson et al. 103150 X 2,798,662 7/1957 Evans 230162 2,832,295 4/1958 Waldherr 103-150 FOREIGN PATENTS 734,294 7/1955 Great Britain.

DONLEY J. STOCKING, Primary Examiner.

LAURENCE V. EFNER, JOSEPH H. BRANSON, JR.,

Examiners. 

1. A FLUID PUMP COMPRISING A HOUSING HAVING AN INLET PORT AND AN EXHAUST PORT THEREIN, VALVE MEANS IN EACH SAID PORT FOR PREVENTING FLUID FLOW THERETHROUGH IN ONE DIRECTION, PERIPHERAL AND INNER SHOULDER MEANS ON SAID HOUSING, ANNULAR DIAPHRAGM MEANS SECURED TO SAID HOUSING ALONG SAID PERIPHERAL SHOULDER MEANS AND SAID INNER SHOULDER MEANS AND FORMING AN ANNULAR FLUID TIGHT CHAMBER COMMUNICATING WITH SAID INLET AND EXHAUST PORTS, A RIGID SUPPORT EXTENDED OVER AND AFFIXED SNUGLY TO A MAJOR PORTION OF SAID DIAPHRAGM MEANS THEREBY MAKING THE MAJOR PORTION OF SAID DIAPHRAGM MEANS SUBSTANTIALLY INFLEXIBLE WHILE PROVIDING FLEXIBLE PORTIONS ADJACENT EACH SAID SHOULDER MEANS, ACTUATING MEANS RECIPROCABLY MOUNTED IN SAID HOUSING, SAID ACTUATING MEANS PASSING THROUGH THE ANNULUS OF SAID DIAPHARGM MEANS AND HAVING SHOULDER MEANS ADAPTED FOR ABUTTING AND EXERTING AN ACTUATING FORCE ON SAID RIGID SUPPORT TO MOVE THE SAME AND SAID DIAPHRAGM MEANS WITH RESPECT TO SAID INLET AND EXHAUST PORTS, AND RESILIENT MEANS EXERTING A REACTION FORCE ON SAID DIAPHRAGM MEANS IN A DIRECTION OPPOSING SAID ACTUATING FORCE TO PRESSURIZED THE FLUID WITHIN SAID PUMP. 